Other health problems

Why Does My Dog Vomit Blood?

Josie F. Turner
By Josie F. Turner, Journalist specialized in Animal Welfare. Updated: February 21, 2023
Why Does My Dog Vomit Blood?

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If your dog bleeds from anywhere, we need to ensure we discover the reason. While a thorn in a paw needs attention, it is not as concerning a symptom as throwing up blood. Although it is possible for a dog to throw up blood and act normal, it is usually concurrent with other symptoms which can help point us in the direction of the cause. One important thing we need to do is distinguish between bright fresh blood and dark digested blood. Knowing the quality of the vomited blood will help guide a veterinarian's diagnosis.

At AnimalWised, we ask why is my dog vomiting blood? While it will require diagnosis from a qualified veterinarian, we can show you some of the main causes of this problem and what treatment options are available to remedy them.

You may also be interested in: Why Does my Dog Vomit Bile?


  1. Is my dog vomiting blood?
  2. Inflammatory diseases of the digestive system
  3. Presence of foreign bodies
  4. Poisoning
  5. Renal insufficiency
  6. Gastric ulcers
  7. Other causes of vomiting blood in dogs
  8. Home remedies for a dog vomiting blood

Is my dog vomiting blood?

Before we explain the possible reasons your dog may be vomiting blood, we need to ensure this is what is actually happening. Although you may see something that looks like blood coming out of your dog's mouth, it may be something else. It also may appear like the dog is throwing up blood from their stomach, but it is possible the blood is coming from elsewhere.

Although the blood or bloody substance may appear to originate in the gastrointestinal system, it is important we know its origin. If you think your dog has vomited blood, check the following:

  • Mouth: if you see fresh blood, it may not actually be coming from their stomach as vomit. If a dog has a severe cut to their mouth, has experienced trauma or has lost a tooth, it can look like they are throwing up blood when they are not. When the dog is bleeding from their mouth, the blood will be bright red. It may be mixed with saliva, but it will not have any food or digested content. Even biting into a stick can pierce their gums and cause mouth bleeding. Although there may be a lot of blood at the beginning, these may be minor wounds and not as concerning as vomiting blood.

  • Respiratory system: if the blood is fresh, but not originating in the mouth, it is possibly from another part of the respiratory system. Although retching and coughing can sound similar, it is possible the dog has coughed up blood from their throat, trachea or even their lungs. The cause of this type of internal bleeding can be varied, ranging from a simple sore throat to something life threatening such as canine pulmonary fibrosis.

  • Digestive system: when the dog does throw up blood from their digestive system, it is known as hematemesis. This blood can be bright red and fresh, even presenting in clots. However, when blood enters the dog's stomach it will come in contact with gastric acid which will start to digest it. Once this happens, the blood will appear much darker. The darker the blood, the more digested it will be. A dog may also vomit blood with foam, mucus or excess liquid.

Sometimes a dog will vomit blood, but also have some blood appear in its stool. Known as melena, these stools will be of a very dark color thanks to containing digested blood. Finally, we must see if a one-off episode of acute vomiting occurs or if we observe vomiting over several days. You need to consider this data as well as looking at other symptoms such as pain, diarrhea or weakness. This will prove useful when bringing your pet to the vet.

If we are sure that the dog is indeed throwing up blood, we should have an idea of its cause. In the following sections, we look at the most common reasons a dog vomits blood.

Why Does My Dog Vomit Blood? - Is my dog vomiting blood?

Inflammatory diseases of the digestive system

If your dog has inflammation of the bowel or any other part of the digestive system then it is common to see blood in the vomit or stool as a symptom. This doesn't happen 100% of the time. If we see the dog vomiting blood, they often will not want to eat or drink. We must seek veterinary advice. Whenever there is bleeding, the dog is vulnerable to a secondary bacterial infection or other complications.

Losing fluid without being able to replenish liquis means dehydration is a great risk. In turn, this aggravates the general clinical picture. The causes of inflammation may be varied, but a particularly serious issue is parvovirus with acute infectious enteritis. This particularly affects puppies and has a high mortality rate. Being a virus, there is no better treatment that prevention. This is done by vaccinating puppies from the ages of 6 to 8 weeks.

Presence of foreign bodies

It is relatively common for dogs to ingest all sorts of objects, especially when they are puppies or have a voracious appetite. These objects can be stones, sticks, bones, toys, hooks, textile or almost anything they can fit in their mouth. Some contain sharp edges and can cause considerable damage to the digestive system when swallowed. This can even include perforation of internal organs.

Although we may be unable to see a foreign body, there are certain signs that may indicate the dog has ingested something they shouldn't. For example, if a dog has something stuck in their throat, you will likely hear gagging noises as the dog tries to expel it.

If we suspect the ingestion of a foreign body as the cause of blood in our dog's vomit, we should go to the veterinarian immediately. By carrying out an x-ray, it is sometimes possible to distinguish the swallowed object and its location. Other times, it is necessary to carry out an endoscopy with which the foreign body can sometimes be extracted. If this is not possible, the treatment will be abdominal surgery.

To avoid these situations prevention is essential. This can be down by not leaving choking hazards around the house. Only offering safe toys and not those made of dangerous materials. Do not try to remove the object yourself. It is possibly sharper than you imagine or even stuck in some tissue. Trying to remove it at home can cause more damage.


Whether accidental or intentional, poisoning can also explain why our dog vomits blood. Some substances, such as rodenticides, act as anticoagulants and cause spontaneous hemorrhages. In addition to vomiting, symptoms may include nosebleeds and/or rectal bleeding. Immediate veterinary attention is required and the progress will depend on the substance ingested and its quantity in relation to the weight of the animal. If we know what poisonous substance the dog has ingested, we must tell the vet.

To prevent accidental poisoning, we need to ensure our pet lives in a safe environment, prohibiting access to toxic products. These include household cleaners or other caustic solutions. When you take the dog for walks or if they have access to the outside, we must also make precautions. This is because there may be garbage, hazardous discarded material or even plants which contain substances poisonous to dogs.

Always keep an eye on your dog when outside and ensure you stop them from eating anything if you don't know what it is. Rapid intervention may be the key to avoiding poison risks. If poisoning occurs, it is usually treated with vitamin K and blood transfusions may be required.

Renal insufficiency

Sometimes the cause of vomiting blood in a dog is due to an underlying systemic disease such as kidney failure in dogs. In this case, the reason the dog vomits blood is as a consequence of the kidneys being unable to eliminate waste products properly. The accumulation of toxins in these waste products is what results in the symptoms.

Although the kidneys are essentially failing, they are able to compensate for a long time. When we finally register the disease, they are often already suffering from renal insufficiency. This insufficiency can occur in an acute or chronic way. In addition to vomiting blood from gastrointestinal bleeding, we can see that our dog drinks and urinates more, seems apathetic, is thinner, has poor coat condition and has a breath which smells of ammonia. Sometimes mouth ulcers and diarrhea are also present.

We can confirm the problem through a blood and urine test. The prognosis will depend on the development of the disease. In chronic cases, treatment usually consists of a specific diet for dogs with renal failure as well as medication. Acute renal failure requires intensive veterinary care with fluid therapy and intravenous medication.

Why Does My Dog Vomit Blood? - Renal insufficiency

Gastric ulcers

An ulcer consists of lesions in the mucosa of the digestive system. They can be superficial or deep and present themselves in various sizes. They may also be the explanation as to why your dog is vomiting blood. Among the causes of ulcers is the use of anti-inflammatory drugs (NSAIDs). Ulcers cause vomiting, but may also be accompanied by anemia and weight loss.

Digested, fresh or clotted blood may be present in these vomits. It is a serious situation since considerable hemorrhage can occur quickly, causing the dog to go into shock. Stools may also appear blackish due to the presence of blood. In addition, the ulcer may end in perforation which can cause peritonitis. Veterinary attention is required and the prognosis is reserved until after examination.

Learn more with our article on the causes and treatment of peritonitis in dogs.

Other causes of vomiting blood in dogs

As we said at the beginning, there are many potential causes of blood being present in a dog's vomit. In addition to the ones mentioned above, there are also potential causes found in the following:

  • Tumors (more frequent in older dogs)
  • Liver or pancreatic diseases
  • Injuries caused by accidents such as falls or collisions
  • Blood disorders

Whatever the reason your dog is throwing up blood, the veterinarian will need to carry out a series of diagnostic tests. These include examination and/or laboratory tests such as blood, urine and feces tests. They may also use exploratory tests such as x-rays, ultrasounds, endoscopies or even exploratory laparotomy.

Wherever there is bleeding, surgery may be the required option. This is because it can often be a serious condition which threatens the life of our dog. As we have already seen, both treatment and prognosis will depend on the origin of the blood in the vomit as well as the speed with which a diagnosis is sought.

Why Does My Dog Vomit Blood? - Other causes of vomiting blood in dogs

Home remedies for a dog vomiting blood

There are minor injuries which may cause mouth bleeding such as removing a splinter from your dog's gum which you can treat at home. Even these minor procedures should be performed carefully, as much for your own safety as for the animal.

If we see our dog has coughed up blood or vomited blood, there are no home remedies to treat it. Even when the problem is not as bad as it seems, it is vital we take the to dog to a veterinarian to diagnose the issue. A dog vomiting blood is a general symptom and can be potentially fatal. Since prompt diagnosis and treatment can be the difference between life and death, it is our responsibility to have the dog medically examined.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Why Does My Dog Vomit Blood?, we recommend you visit our Other health problems category.

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Why Does My Dog Vomit Blood?